Gene conversion involving the pilin structural gene correlates with pilus+ ⇄ pilus− changes in Neisseria gonorrhoeae
1986; Cell Press; Volume: 47; Issue: 2 Linguagem: Inglês
10.1016/0092-8674(86)90449-6
ISSN1097-4172
AutoresJ Swanson, Sven Bergström, Kenneth E. Robbins, O Barrera, Dan Corwin, Michael Koomey,
Tópico(s)RNA and protein synthesis mechanisms
ResumoGonococci (Gc) exhibit pilus+----pilus- "phase transitions" at high frequency, but only some of the pilus- Gc can revert to pilus+ phenotype. We examined reversible phase transitions between pilus+ Gc and a particular pilus- variant (P-rp+ phenotype) whose pilin mRNA carries a unique block of nucleotides encoding an "assembly missense" pilin polypeptide. The results show that Gc pilus+ in equilibrium with P-rp+ transitions can result from intragenic recombination in which there is nonreciprocal exchange of partially homologous DNA sequences from a partial pilin gene (in silent, storage form) into the expression locus' complete pilin gene. Hence Gc pilus phase variation, like pilus antigenic variation, can occur by gene conversion of the pilin structural gene expression locus.
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